2NaN3 ---> 2Na + 3N2
An unknown amount of sodium azide (NaN3) reacts and produces 0.033 moles of nitrogen gas. What mass of sodium metal is produced?

g

Rounded to 3 significant figures

0.51g

Explanation:

2NaN3 ---> 2Na + 3N2

From the balanced reaction equation, we can be able to forge ahead in solving the question.

We can see from the equation that 2 moles of sodium azide yields 3 moles of nitrogen gas

x moles of sodium azide yields 0.033 moles of nitrogen gas

x= 0.033×2/3= 0.022 moles of sodium azide.

From the reaction equation, we can also see that;

2 moles of sodium azide yielded 2 moles of sodium

0.022 moles of sodium azide will yield 0.022 × 2/2= 0.022 moles of sodium metal.

Molar mass of sodium metal= 23 gmol-1

Mass of sodium produced= 0.022 moles of sodium metal × 23 gmol-1= 0.506g

0.506g

Explanation:

Step 1:

The balanced equation for the reaction. This given below:

2NaN3 —> 2Na + 3N2

Step 2:

Determination of the number of mole of sodium azide (NaN3) that reacted to produce 0.033 mole of nitrogen gas (N2).

This is illustrated below:

From the balanced equation above,

2 moles of Na3N reacted to produce 3 moles of N2.

Therefore, Xmol of Na3N will react to produce 0.033 mole of N2 i.e

Xmol of Na3N = (2 x 0.033)/3

Xmol of Na3N = 0.022 mole.

Therefore, 0.022 mole of Na3N reacted.

Step 3:

Determination of the number of mole of Na produced from the reaction. This is illustrated below:

From the balanced equation above,

2 moles of Na3N reacted to produce 2 moles of Na.

Therefore, 0.022 mole Na3N will also produce 0.022 mole of Na.

Step 4:

Conversion of 0.022 mole of Na to grams. This is illustrated below:

Number of mole Na = 0.022 mole

Molar Mass of Na = 23g/mol

Mass of Na =.?

Mass = number of mole x molar Mass

Mass of Na = 0.022 x 23

Mass of Na = 0.506g

Therefore, 0.506g of sodium (Na) is produced

it should be all of them because it asks if you included all of those in your answer

explanation:

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”